1. Field of the Invention
The present invention relates generally to multiple-cycle internal combustion engines and, more specifically, to a trainable, scavenger-ported piston with two and four-cycle capabilities.
2. Description of the Prior Art
There are other variable cycle pistons designed for internal combustion engines. Typical of these is U.S. Pat. No. 5,699,758 issued to John N. Clarke on Dec. 23, 1997.
Another patent was issued to Marius A. Paul et al. on May 21, 1996 as U.S. Pat. No. 5,517,951. U.S. Pat. No. 5,193,492 was issued on Mar. 16, 1993 to Hideo Kawamura. Yet another U.S. Pat. No. 5,007,382 was issued to Hideo Kawamura on Apr. 16, 1991.
A method for operating a reciprocating piston-type internal combustion engine selectively in two-stroke, four-stroke, and six-stroke mode includes; providing transfer valves, transfer passage means between piston cylinders, selectively controlling the actuation and timing of the intake, exhaust, and transfer valves, and alternatively operating the intake and exhaust valves for each piston cylinder in overlapping sequence during each crankshaft revolution to provide two-stroke operation, operating the intake and exhaust valves in sequence during each second crankshaft revolution to provide four-stroke operation, operating the intake, exhaust, and transfer valves sequentially to cause a secondary expansion stroke in an adjacent piston cylinder to provide six-stroke operation of the engine.
A universal internal combustion engine that is electronically and reversibly convertible from four-stroke operation to two-stroke operation, the engine having intake and exhaust valves with an electro-hydraulic actuator system for actuating the valves in accordance with electronic control signals from an electronic control module, the electro-hydraulic actuator system having an electronic actuator for each valve coupled to a slide valve for a discrete supply of pressurized hydraulic fluid to a hydraulic piston for each valve, the electronic control module having a program for independent activation of each electronic actuator for select operation of each intake and exhaust valve at any time during the operating cycle.
The present invention lies in a 2-4 cycle change-over engine and it=s control unit which perform 2 cycle running of the uniflow type by closing a suction valve at an upper portion of the engine and working a valve (a rotational sleeve) at a lower portion of a cylinder when the engine rotates in a lower number of revolution than a predetermined number of revolution and a load is larger than a predetermined value, and perform changeover into 4-cycle running by always closing a scavenging port at a lower portion of the cylinder by means of the valve (the rotational sleeve) at the lower portion of the cylinder and working the suction valve at the upper portion of the cylinder when a higher revolution than a predetermined number of revolution is given and an engine load is lighter than a predetermined load.
This cycle changeable engine includes first intake valves for a four-cycle operation which are disposed in intake ports formed in a cylinder head, exhaust valves disposed in exhaust ports, second intake valves for a two-cycle operation, disposed in intake ports formed at the lower part of a cylinder, and an electromagnetic valve driving device for opening and closing each of the valves by electromagnetic force. The engine includes also a controller which actuates either the first or second intake valves for opening and closing with the others being kept closed in response to a detection signal from detection means for detecting the number of revolutions or the load of the engine, and changes the operational condition of the engine to the two-cycle or four-cycle operation. In this manner the engine is operated in the two-cycle operation at a low speed revolution of the engine to improve an output torque and is operated in the four-cycle operation at a high-speed revolution of the engine to reduce fuel consumption, to improve mean effective pressure and volume efficiency and to
While these variable-cycle engines may be suitable for the purposes for which they were designed, they would not be as suitable for the purposes of the present invention, as hereinafter described. For example, the prior art does not provide a variable-cycle engine that utilizes a rotating piston to selectively open and close the appropriate ports for the two-cycle and four-cycle modes, respectively.
A primary object of the present invention is to provide an engine that can switch back and forth between two-cycle and four-cycle operational modes as needed due to a piston tail that rides along a training block within the cylinder wall. As the piston travels vertically the piston tail is training within a recess in the training block thereby rotating the piston head incrementally and aligning various ports to perform their respective functions.
Another object of the present invention is to provide a variable-cycle engine with a trainable piston that is governed by a microprocessor that adjust cycling according to load requirements picked up by sensors.
Yet another object of the present invention is to provide a variable-cycle engine with a trainable piston that utilizes cylinder porting, piston ports, and scavenging ports in the cylinder wall to supply fuel to the combustion chamber.
Still yet another object of the present invention is to provide a ball and socket means for attaching the connecting rod to the piston head thereby enabling the piston head to rotate when training.
Yet another object of the present invention is to provide a multiple-cycle engine that is efficient to operate yet can increase power capacity when necessary.
Additional objects of the present invention will appear as the description proceeds.
The present invention overcomes the shortcomings of the prior art by providing an internal combustion engine that can maintain the low weight, simplicity, and high power output of a two-cycle engine and switch over to a four-cycle operation for lower emissions and greater fuel economy when under normal operating conditions, by means of a computer-operated trainable piston assembly.
The present invention provides the means to maintain the low weight, simplicity and high power output of the two-cycle engine while under load, and yet maintain the lower emissions and higher increased economic requirements of the four-cycle engine under normal operating conditions. A ported, scavenging piston is connected to the crankshaft by means of a connecting rod, which has a ball-shaped (male) configuration on the upper end and links into the piston socket (female), which allows for the required multi-positioning of the piston. The connecting rod is linked to the crankshaft by means of a free spinning bearing.
When not under load, or at low RPM, the engine shall run in the four-cycle mode, by means of the trainable piston, which will be positioned by means of a training block, which is located within the cylinder wall. The piston is aligned by the training block by a piston tail that slides within the training block. The training block is computer controlled for two and four-cycle modes.
While in the four stroke mode the piston starts out in the upper position and travels down within the cylinder, being trained by means of the piston tail following the training block. A fuel charge is drawn through the piston from the intake port runner located in the cylinder wall, and travels through the piston port to the adjacent four-cycle scavenging port runner, and on into the combustion chamber. The piston is then trained counter-clockwise 35xc2x0 by means of the training block, and starts it""s upward travel for the compression stroke.
At full compression the spark plug fires causing detonation of the fuel and the piston travels down for the power stroke. The piston is again trained counter-clockwise 35xc2x0 by means of the training block, and starts it""s upward travel for the exhaust-purging stroke.
For the fourth and final cycle of the four-cycle mode, the piston is trained, by means of the training block, returning to the first position for the down and intake stroke.
Under a load or at a higher RPM where the two-cycle operation is self-sustaining because intake charge is scavenged by means of a megaphone exhaust at high RPM""s, the piston is trained by means of the training block to a fourth position to align the intake runner and two-cycle scavage runner, and starts its downward motion. Again a fuel charge is drawn through the piston from the intake port runner located in the cylinder wall and travels through the piston port, this time in the opposite direction, to the adjacent two-cycle scavenging port runner, and on into the combustion chamber. The exhaust cycle occurs simultaneously. The piston is then trained to a fifth position so that all ports are sealed and begins its upward travel for the compression stroke. At full compression the spark plug fires causing detonation of the fuel and the piston travels down for the power stroke. The piston is then repeatedly moved between the fourth and fifth positions (intake/exhaust [Position 4] and power/compression [Position 5] of two-cycle operation).
Exhaust vents in the piston head allow for the variation in piston positioning for all operations of the two and four-cycle modes.
A variable-cycle engine capable of alternating between two-cycle and four-cycle operation is provided, comprising: a cylinder block having at least one piston cylinder and a piston reciprocable in the cylinder, the cylinder block further having a crankshaft and a connecting rod, the cylinder further having a training block, the training block being movable about the inner periphery of the cylinder; the connecting rod connecting the piston and the crankshaft such that the piston may rotate within the cylinder on the connecting rod; the piston having a top and a side; the piston further having a piston port, the piston port having a first end on the piston side and a second end on the piston side; the piston further having a first and second exhaust vent, each such exhaust vent having an exhaust intake end on the piston top and an exhaust discharge end on the piston side; the piston further having a tail member extending to and received by the training block such that the piston rotates within the cylinder as the training block moves; a training block driving assembly for causing the training block to sequentially and repeatedly move from a first to a second to a third position for four-cycle operation, and, alternatively for causing the training block to sequentially and repeatedly move from a fourth to a fifth position for two-cycle operation, the movement of the training block causing the piston to rotate into five rotation positions corresponding with the five positions of the training block; a fuel charge intake port alignable with the piston port first end, when the piston is in the first rotation position, such that the fuel charge is scavenged from the intake port into the piston port first end, such scavenging being terminated when the piston is in the second rotation position; a first scavage port positioned such that, when the piston is in the first rotation position, the piston port second end discharges the fuel charge into the first scavage port and the first scavage port discharges the fuel charge into the cylinder above the piston top, the first scavage port being further positioned such that the fuel charge discharge into the first scavage port is terminated when the piston is in the second rotation position; an exhaust port positioned for receiving exhaust from the piston first exhaust vent discharge end when the piston is in the third rotation position; and a second scavage port positioned such that, when the piston is in the fourth rotation position, the intake passage discharges the fuel charge into the piston port second end, the piston port first end discharges the fuel charge into the second scavage port, and the second scavage port discharges the fuel charge into the cylinder above the piston top, the second scavage port being further positioned such that the fuel charge discharge from the second scavage port terminates when the piston is in the fifth rotation position, the exhaust port, in this fifth rotation position, being aligned to receive exhaust from the piston second exhaust vent discharge end.
In another embodiment, the training block driving assembly further comprises at least one engine operational condition detector and a controller, the controller analyzing the detected engine operating conditions and adjusting training block movement in accordance with predetermined conditions necessitating such an adjustment.
In another embodiment, the controller includes a microprocessor.
In another embodiment, the training block driving assembly selects either two-cycle or four-cycle operation in response to at least one of the detectors measuring engine speed.
In another embodiment, the training block driving assembly selects either two-cycle or four-cycle operation in response to at least one of the detectors measuring engine load.
In another embodiment, the training block driving assembly selects either two-cycle or four-cycle operation in response to at least two of the detectors measuring engine load and speed, respectively.
In another embodiment, the training block driving assembly switches between two-cycle to four-cycle training block movement in response to an overriding manually entered input.
In another embodiment, the training block driving assembly utilizes electromagnetic forces for moving the training block.
In another embodiment, the training block driving assembly switches from two-cycle to four-cycle training block movement in response to manually entered input.
In another embodiment, the training block driving assembly utilizes electromagnetic forces for moving the training block.
In another embodiment, the connecting rod further comprises a ball, and the piston further comprises a socket for mating with the ball to form a ball and socket joint.
A variable-cycle engine capable of alternating between two-cycle and four-cycle operation is provided, comprising: a cylinder block having at least one piston cylinder and a piston reciprocable in the cylinder, the cylinder block further having a crankshaft and a connecting rod; the connecting rod connecting the piston and the crankshaft such that the piston may rotate within the cylinder on the connecting rod; the piston having a top and a side; the piston further having a piston port, the piston port having a first end on the piston side and a second end on the piston side; the piston further having a first and second exhaust vent, each such exhaust vent having an exhaust intake end on the piston top and an exhaust discharge end on the piston side; means for sequentially and repeatedly training the piston from a first to a second to a third rotation position for four-cycle operation, and, alternatively, for sequentially and repeatedly the piston from a fourth to a fifth rotation position for two-cycle operation; a fuel charge intake port alignable with the piston port first end, when the piston is in the first rotation position, such that the fuel charge is scavenged from the intake port into the piston port first end, such scavenging being terminated when the piston is in the second rotation position; a first scavage port positioned such that, when the piston is in the first rotation position, the piston port second end discharges the fuel charge into the first scavage port and the first scavage port discharges the fuel charge into the cylinder above the piston top, the first scavage port being further positioned such that the fuel charge discharge into the first scavage port is terminated when the piston is in the second rotation position; an exhaust port positioned for receiving exhaust from the piston first exhaust vent discharge end when the piston is in the third rotation position; and a second scavage port positioned such that, when the piston is in the fourth rotation position, the intake passage discharges the fuel charge into the piston port second end, the piston port first end discharges the fuel charge into the second scavage port, and the second scavage port discharges the fuel charge into the cylinder above the piston top, the second scavage port being further positioned such that the fuel charge discharge from the second scavage port terminates when the piston is in the fifth rotation position, the exhaust port, in this fifth rotation position, being aligned to receive exhaust from the piston second exhaust vent discharge end.
In another embodiment, the means for training the piston comprises at least one engine operational condition detector and a controller, the controller analyzing the detected engine operating conditions and adjusting piston training in accordance with predetermined conditions necessitating such an adjustment.
A variable-cycle engine capable of alternating between two-cycle and four-cycle operation is provided, comprising: a cylinder block having at least one piston cylinder and a piston reciprocable in the cylinder, the cylinder block further having a crankshaft and a connecting rod, the cylinder further having a training block, the training block being movable about the inner periphery of the cylinder; the connecting rod further having a ball and the piston further having a socket for mating with the ball to form a ball and socket joint, such that the piston may rotate within the cylinder on the connecting rod; the piston having a top and a side; the piston further having a piston port, the piston port having a first end on the piston side and a second end on the piston side; the piston further having a first and second exhaust vent, each such exhaust vent having an exhaust intake end on the piston top and an exhaust discharge end on the piston side; the piston further having a tail member extending to and received by the training block such that the piston rotates within the cylinder as the training block moves; a detector for detecting the operational conditions of the engine; at least one sensor for detecting engine speed and engine load, and a microprocessor, the microprocessor analyzing the sensed engine operating conditions; a training block driving assembly for receiving signals from the microprocessor and selectively causing the training block to sequentially and repeatedly move from a first to a second to a third position for four-cycle operation, and, alternatively, for selectively causing the training block to sequentially and repeatedly move from a fourth to a fifth position for two-cycle operation, the movement of the training block causing the piston to rotate into five rotation positions corresponding with the five positions of the training block, the microprocessor signals causing the training block driving assembly to move the training block movement in accordance with predetermined conditions necessitating such movement; a fuel charge intake port alignable with the piston port first end, when the piston is in the first rotation position, such that the fuel charge is scavenged from the intake port into the piston port first end, such scavenging being terminated when the piston is in the second rotation position; a first scavage port positioned such that, when the piston is in the first rotation position, the piston port second end discharges the fuel charge into the first scavage port and the first scavage port discharges the fuel charge into the cylinder above the piston top, the first scavage port being further positioned such that the fuel charge discharge into the first scavage port is terminated when the piston is in the second rotation position; an exhaust port positioned for receiving exhaust from the piston first exhaust vent discharge end when the piston is in the third rotation position; and a second scavage port positioned such that, when the piston is in the fourth rotation position, the intake passage discharges the fuel charge into the piston port second end, the piston port first end discharges the fuel charge into the second scavage port, and the second scavage port discharges the fuel charge into the cylinder above the piston top, the second scavage port being further positioned such that the fuel charge discharge from the second scavage port terminates when the piston is in the fifth rotation position, the exhaust port, in this fifth rotation position, being aligned to receive exhaust from the piston second exhaust vent discharge end.
A method for alternating between two-cycle and four-cycle operation of an internal combustion engine is provided, comprising the steps of: connecting a piston to a crankshaft such that the piston is rotatable within a cylinder and reciprocable within the cylinder; positioning the piston in a first rotation position such that a fuel charge intake port scavenges a fuel charge from a piston port first end, then out a piston port second end, then into a first scavage port runner, then into a combustion chamber; positioning the piston in a second rotation position such that the combustion chamber is sealed for compression and ignition; positioning the piston in a third rotation position such that the exhaust from the ignition enters a first piston exhaust vent, then exits the first piston exhaust vent into a cylinder exhaust port, and then exits the cylinder; for two-cycle positioning the piston in a fourth rotation position such a fuel charge intake port scavenges a fuel charge from a piston port second end, intake charge is scavenged by a megaphone type exhaust then out a piston port first end, then into a second scavage port runner, then into a combustion chamber, while, simultaneously, exhaust enters a second piston exhaust vent, then exits the second piston exhaust vent into the cylinder exhaust port, and then exits the cylinder; and positioning the piston in a fifth rotation position such that the combustion chamber is sealed for combustion and ignition.
In another embodiment, the method further comprises the step of switching between two-cycle and four-cycle operation in response to measured engine operating conditions.
The foregoing and other objects and advantages will appear from the description to follow. In the description reference is made to the accompanying drawing, which forms a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and the structural changes may be made without departing from the scope of the invention. In the accompanying drawing, like reference characters designate the same or similar parts throughout the several views.
The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims.